Freezing of Gait Is Associated with Daily Activity Limitations among Individuals with Parkinson's Disease and Mild Cognitive Impairment

This study investigated the relationship between freezing of gait and daily activities among individuals with mild cognitive impairment due to Parkinson's disease by determining differences in caregiver-reported daily activity performance between individuals with and without freezing of gait. Cross-sectional baseline data from a longitudinal cohort study were used with 24 participants. Caregivers completed the Activities of Daily Living Questionnaire (ADLQ). Using a Mann-Whitney U test, findings indicated that participants with freezing of gait reported overall higher functional impairment levels on the ADLQ (p=.001), including the household, travel, self-care, employment and recreation, and communication subscores, indicating more perceived impairment. Findings show freezing of gait is associated with daily activity limitations in the home and the community among individuals with mild cognitive impairment due to Parkinson's disease. Clinicians should consider assessing freezing of gait, as early detection can inform the selection of interventions and strategies to minimize its impact on the performance of daily activities.

Motor Memory Consolidation Deficits in Parkinson's Disease: A Systematic Review with Meta-Analysis

BACKGROUND

The ability to encode and consolidate motor memories is essential for persons with Parkinson's disease (PD), who usually experience a progressive loss of motor function. Deficits in memory encoding, usually expressed as poorer rates of skill improvement during motor practice, have been reported in these patients. Whether motor memory consolidation (i.e., motor skill retention) is also impaired is unknown.

OBJECTIVE

To determine whether motor memory consolidation is impaired in PD compared to neurologically intact individuals.

METHODS

We conducted a pre-registered systematic review (PROSPERO: CRD42020222433) following PRISMA guidelines that included 46 studies.

RESULTS

Meta-analyses revealed that persons with PD have deficits in retaining motor skills (SMD = -0.17; 95% CI = -0.32, -0.02; p = 0.0225). However, these deficits are task-specific, affecting sensory motor (SMD = -0.31; 95% CI -0.47, -0.15; p = 0.0002) and visuomotor adaptation (SMD = -1.55; 95% CI = -2.32, -0.79; p = 0.0001) tasks, but not sequential fine motor (SMD = 0.17; 95% CI = -0.05, 0.39; p = 0.1292) and gross motor tasks (SMD = 0.04; 95% CI = -0.25, 0.33; p = 0.7771). Importantly, deficits became non-significant when augmented feedback during practice was provided, and additional motor practice sessions reduced deficits in sensory motor tasks. Meta-regression analyses confirmed that deficits were independent of performance during encoding, as well as disease duration and severity.

CONCLUSION

Our results align with the neurodegenerative models of PD progression and motor learning frameworks and emphasize the importance of developing targeted interventions to enhance motor memory consolidation in PD.

Training in varying environmental contexts facilitates transfer of improved gait performance to new contexts for individuals with Parkinson's disease - a randomized controlled trial

OBJECTIVE

To investigate whether varying practice context during gait training could reduce context-dependency and facilitate transfer of improved gait performance to a new context.

DESIGN

A single-blind, parallel-group randomized controlled trial.

SETTING

Medical university rehabilitation settings.

PARTICIPANTS

Forty-nine participants with PD were recruited and randomized into the constant (CONS) or varied (VARI) context group.

INTERVENTIONS

All participants received 12 sessions of treadmill and over-ground gait training. The CONS group was trained in a constant environmental context throughout the study, while the VARI group received training in 2 different contexts in an alternating order.

MAIN OUTCOME MEASURES

The primary outcome was gait performance, including velocity, cadence, and stride length. The participants were assessed in the original training context as well as in a novel context at post-test to determine the influence of changed environmental context on gait performance.

RESULTS

While both groups improved significantly after training, the CONS group showed greater improvement in stride length than the VARI group when assessed in the original practice context. However, the CONS group showed a decreased velocity and stride length in the novel context, while the VARI group maintained their performance.

CONCLUSIONS

Varying practice context could facilitate transfer of improved gait performance to a novel context.

The effect of context variability on motor learning

Although the practice schedule and variation in incidental context have been investigated together, it is not clear whether just variation in incidental context can beneficiate motor learning. Therefore, the present study aimed to investigate the effect of context variability on motor learning. We hypothesized the practice in a variable incidental context would enable learners to be more resistant to the effects of the contextual changes when compared to a constant incidental context practice. Twenty-four participants were assigned to one of the two groups: constant incidental context (G_CC) or variable incidental context (G_VC). During practice, the G_CC practiced a sequence keypressing task in one color and a position showed on the computer screen. The G_VC practiced the same sequence in four different combinations of color and position. Twenty four hours, the same contexts practiced on practice (SAME) was performed and immediately after, a new sequential movement in new color and new position (SWITCH) was performed. The results indicated that the G_VC showed better performance than the G_CC on the SWITCH condition, mainly in measures related to planning/selection process. The results were explained by degree of similarity among processing events engaged during different moments and by development of a filter of information based on attentional selection.